High air flow capacity with excellent energy efficiency. Low energy consumption. Direct drive system and patented louver opening device. Fan housing and Venturi are made of hard galvanized steel. Long service life with a high-coated galvanized casing. High capacity with specially designed stainless blades. Automatic opening and closing of louvers with a shaft system. High insulation with louver plastics. Magneliz coating against erosion and rust. Lower electricity consumption due to its 3 blades. No belt system. Fan blades are directly connected to the motor shaft.